Our laboratory has developed experience with cationic Liposome based gene transfer. We have applied this methodology to CFTR delivery in preclinical studies to human respiratory epithelial cells in vitro, as well as to mammalian respiratory epithelium in vivo. In addition, preclinical studies of gene transfer using cationic liposomes have rapidly led to development of a human clinical trial of CFTR transfer using a DMRIE/DOPE vehicle. These basic and preclinical developments have Created the need for a formal means for initiating therapeutic, clinical trials involving CF patients. This project intends to provide the resources necessary to develop and complete a clinical trial of CFTR gene transfer to the nasal airway in 9 CF patients using cationic Iiposomes. This study is the first step towards future trials of liposome based CFTR therapy, including evaluation of repeated nasal administration of CFTR, lower airway administration of Iipid/DNA conjugates to CF patients, and studies of other cationic lipids or lipid/DNA ratios during in vivo human gene administration. We will perform clinical assays necessary to facilitate future human studies of CF at the UAB center. These assays include 1) measurement of nasal potential difference; 2) RT-PCR detection of normal CFTR mRNA following gene transfer; 3) primary culture of airway epithelial cells following in vivo gene transfer; and 4) CFTR mutation analysis. We will also examine the mechanisms of gene delivery and expression underlying lipid based gene transfer in vitro and in vivo. The principles and approaches developed within this project will form a solid foundation for future studies of liposomal CFTR gene therapy.